In a semiconductor manufacturing process, thin semiconductor wafers are carried or accommodated in a wafer container when transported between processing steps or moved or stored in each individual processing step to prevent the semiconductor wafers from being damaged or contaminated. There has been proposed a wafer container having a plurality of wafer trays superimposed over each other to accommodate each individual semiconductor wafer in an interior space formed between a pair of adjacent wafer trays so that semiconductor wafers can be safely accommodated therein independently of each other (for example, see Patent Document 1).
To safely accommodate semiconductor wafers, which have become fragile as the result of being extremely reduced in thickness in recent years, a wafer container with cushion sheets has been proposed in which a single semiconductor wafer is held between two cushion sheets in an interior space formed between two wafer trays. By being held between the cushion sheets, the semiconductor wafer is prevented from being damaged by an external force such as vibration or impact (for example, see Patent Document 2).    Patent Document 1: Japanese Patent Application Publication No. 2003-168731    Patent Document 2: Japanese Patent Application Publication No. 2005-191419